Limit rational function without L'H

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Homework Help Overview

The discussion revolves around evaluating the limit of a rational function as x approaches 0 from the positive side, specifically the expression lim_{x->0+} \frac{\sqrt{x}}{\sqrt{\sin x}}. The subject area includes limits and properties of functions, particularly in the context of calculus.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the form of the limit, noting it is 0/0, and explore alternative methods to L'Hôpital's Rule. Some suggest considering the limit of x/sin(x) and the continuity of the square root function for positive arguments.

Discussion Status

The discussion is active, with participants sharing insights about the limit and questioning the necessity of using L'Hôpital's Rule. There is a focus on exploring different approaches and clarifying concepts related to the limit evaluation.

Contextual Notes

There is mention of the limit being in the indeterminate form 0/0, which raises questions about the appropriate methods to apply. Participants are considering the implications of continuity and the conditions under which limits can be evaluated.

whatlifeforme
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Homework Statement


evaluate.


Homework Equations


[itex]lim_{x->0+} \frac{\sqrt{x}}{\sqrt{sinx}}[/itex]


The Attempt at a Solution


i've tried l'hopital's and it is just endless cycle.
 
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It's the same as sqrt(x/sin(x)). You know the limit of x/sin(x), right?
 
whatlifeforme said:

Homework Statement


evaluate.


Homework Equations


[itex]lim_{x->0+} \frac{\sqrt{x}}{\sqrt{sinx}}[/itex]


The Attempt at a Solution


i've tried l'hopital's and it is just endless cycle.
Sometimes, L'Hopital's Rule is not the way to go. Under the right conditions, you can switch the order of the limit operation and the function in the limit.
## \lim f(g(x)) = f(\lim g(x))##

Also, as long as all quantities are positive,
$$ \frac{\sqrt{a}}{\sqrt{b}} = \sqrt{\frac{a}{b}}$$
 
yes, but it is of the form 0/0.
 
whatlifeforme said:
yes, but it is of the form 0/0.

That doesn't mean you HAVE to use l'Hopital. You know the limit of x/sin(x), use l'Hopital on that. Then take the square root. Use that the square root is continuous for positive arguments.
 

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